This document discusses asexual and sexual reproduction. Asexual reproduction involves one parent producing genetically identical offspring through mitosis or budding. Sexual reproduction involves two parents each contributing half of the genetic material to produce offspring with a unique combination of genes. While asexual reproduction is faster, sexual reproduction produces more variation and improves adaptation to environmental changes. Some organisms use both reproductive methods.

1. Unit 2 Lesson 3 Sexual and Asexual Reproduction
Essential Question: How do organisms reproduce?
Copyright © Houghton Mifflin Harcourt Publishing Company
Big Idea: Characteristics from parents are
passed to offspring in predictable ways

2. One Becomes Two
What is asexual reproduction?
• Reproduction involves various kinds of cell
division.
• Most single-celled organisms and some
multicellular organisms reproduce asexually.
• In asexual reproduction, one organism
produces one or more new organisms that
are genetically identical to itself.
Unit 2 Lesson 3 Sexual and Asexual Reproduction p114

3. How do organisms reproduce asexually?
• The organism that produces the new organism or
organisms is called a parent.
• Each new organism is called an offspring.
• The offspring produced by asexual reproduction are
genetically identical to their parents.
• Prokaryotes, including bacteria, reproduce asexually by cell
division.
• Some eukaryotes, including many multicellular organisms,
reproduce asexually by more complex processes—types of
cell division called mitosis.
Unit 2 Lesson 3 Sexual and Asexual Reproduction P114-115

4. How do organisms reproduce asexually?
• Binary fission is the form of
asexual reproduction in
prokaryotes.
• Cell division
• Parent Cell splits into two
• Budding occurs when a bud
grows on an organism and
develops into a full-sized
organism.
• Budding is the result of
mitosis.
Unit 2 Lesson 3 Sexual and Asexual Reproduction P115

5. How do organisms reproduce asexually?
• A spore is a specialized cell that
can survive harsh conditions.
• Spores, produced asexually by
one parent, are light and can be
carried by the wind.
• Some plants can reproduce
asexually by vegetative
reproduction.
• Vegetative reproduction happens
through mitosis.
• New plants grow from stems,
roots, or leaves.
• Runners, tubers, plantlets
• Drop off plant and grow on their
own
Unit 2 Lesson 3 Sexual and Asexual Reproduction P115

6. Two Make One
What is sexual reproduction?
• Most multicellular organisms can reproduce sexually.
• In sexual reproduction, two parents each contribute a sex
cell to the new organism.
• Half the genes in the offspring come from each parent.
• Males produce sex cells called sperm cells.
• Females produce sex cells called eggs.
• Sex cells are produced by meiosis.
• Sex cells have half of the set of genetic material found in body
cells.
Unit 2 Lesson 3 Sexual and Asexual Reproduction P116

7. What is sexual reproduction?
• Sex cells have half of the set of genetic material found in
body cells.
• A sperm and an egg join together in a process called
fertilization.
• When an egg is fertilized by a sperm cell, a new cell, called
a zygote, is formed. It has a full set of genetic material.
• The zygote develops into a new organism. It grows through
mitosis.
Unit 2 Lesson 3 Sexual and Asexual Reproduction P116

8. Unit 2 Lesson 3 Sexual and Asexual Reproduction
Odd Reproduction
• Multicellular organisms can
reproduce asexually.
• Some do this by
parthenogenesis, in which
the female produces young
without fertilization.
• Other organisms reproduce
asexually by regeneration.
• Other organisms reproduce
asexually by fragmentation,
in which segments fall off and
become new organisms.
P117

9. Advantages Disadvantages
Asexual Reproduction
Sexual Reproduction
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
P118-119

10. Added Advantage
Copyright © Houghton Mifflin Harcourt Publishing Company
What are the advantages of each type
of reproduction?
• Asexual reproduction has its advantages.
• It allows an organism to reproduce very quickly,
and ensures that any favorable traits the parent
has are passed on to the offspring.
• Reproduction can occur without a partner, and all
offspring can reproduce.
Unit 2 Lesson 3 Sexual and Asexual Reproduction P117-118

11. What are the advantages of each type
of reproduction?
• Sexual reproduction has its advantages.
• It increases genetic variation. Offspring have
different traits, which improves the chance that at
least some will survive.
• Some organisms can use both types of
reproduction. This allows them to spread quickly,
and adapt to changes in the environment as well.
Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 2 Lesson 3 Sexual and Asexual Reproduction P117-118

12. Advantages Disadvantages
Asexual Reproduction
Sexual Reproduction
• Quick
• Does not need a
partner
• Offspring are identical
• All offspring are able
to produce more
offspring
• Can produce many
offspring at one time
• Increases genetic
variation – offspring
are not identical to
parent
• Increases chance of
survival in changing
environments
• Requires complex
structures
• Cannot adapt to a
changing
environment.
• No genetic variation
(unless mutation
occurs)
•
• Slow
• Does require
partner
(relationships)
•
P117-118